The shedding machine is of the type that the movements of the individual shedding means, for example heald frames or Jacquard hooks or wires, can be controlled, that is to say activated or deactivated, through an electronic control in an individually programmable manner by electromechanical elements. Such shedding machines are known to the skilled worker under the name dobby or Jacquard machine. In dobby or Jacquard machines in the sense of this invention, a drive of the main shaft of the shedding machine and rotating masses of the shedding machine connected therewith, including possibly present additional inertial or balancing masses, is possible independent of the actuatable movement of the shedding means. A dobby machine that works according to this principle is described, for example, in the EP 570 628 A1. In contrast to shedding machines in which each shedding means comprises its own motor, a shedding machine as it is pertinent here as an underlying basis needs only a single drive motor.
Moreover, in the present method, one speaks of electric motorized drives which have a changeable rotational speed through an electronic control, and which are able to drive the weaving and the shedding machine with their regular operating rotational speed.
An independent motorized drive of the shedding machine makes it possible, in certain operating conditions, to suspend the operation, which is essentially synchronous in normal weaving operation, of the shedding machine and weaving machine. At this point, reference is made to the fact that both the weaving machine as well as the shedding machine have components that are moved unequally or irregularly or non-continuously in most cases via drive means. In the weaving machine these are usually the components for the reed beat-up and if applicable components for the mechanical weft insertion. In the shedding machine these are the shedding means. The irregular movements of these components cause inertial moments that fluctuate independently of one another on the shaft of the respective drive motor. These in turn cause fluctuating rotational speeds over respectively one operating or working cycle of the weaving and shedding machine. Depending on the size of the drive units and depending on how the associated drive control is laid out or designed in terms of the regulation technology, these fluctuations turn out larger or smaller. This factual situation is described, among other things, in the EP 0 893 525 A1. That means that the weaving and the shedding machine with drive motors that are independent of one another, generally over the course of one working cycle are angularly synchronous and physically exactly at the same rotational speed only at certain functionally absolutely necessary time points. In other angular ranges of a working cycle, it is permissible to deviate from this exact synchronicity. In this regard, an essentially synchronous operating manner means that e.g. within one working cycle the instantaneous rotational speed of weaving or shedding machine amounts to only 85% of the actual operating rotational speed, however that both machines run with the same operating rotational speed when averaged over several working cycles. For the described operating manner it is necessary that the weaving and shedding machine, or their drives in connection with the associated electronic control or regulating arrangements including rotational angle transducers or other sensors, are equipped to allow a determination of the instantaneous position of weaving and shedding machine as well as a synchronizing of both.